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.of Its Values, of which UNITED .sTArEs rnrnnr orrica MARK W. MABSDEN,OE PHILADELPHIA, PENNSYLVANIA.

rims-rum or mcE-smw For. RECOVERY or ns VALUES,

No Drawing.

and- State to Pennsylvania, have invented certain new and usefulImprovements in the Treatment of Rice-Straw for Recovery the followingis a specification.

This invention relates to a method of treating-rice straw .for therecovery of its values.

'Rice straw is ractically a waste material and is frequent y disposed ofb burning.

To a small extent it is employe for packing and crating, and some efforthas been made to utilize 1t as a cattle food, but it is unsuitable forthis purpose unless combined with other 'and more palatable and-nutritive food constituents. It has also been proposed to utilize thefiber for paper making, but the treatments were too harsh" and nothingpracticable was accomplished in this direction. I a

Rice "straw is too valuable to be employed 'solely for the purposesaforementioned, in-

cluding paper making. The available fiber amounts to from thirty toforty-two er cent. Hence with the old methods of ii er liberation thereis a loss of from'slxty to seventy er cent.

The 0 2.1101 the available fiber in all of its Inherent strength and torecover the by-products that heretofore have been lost in the recoveryof the fiber. v

In practising the invention I first subject the straw to a steamingprocess until it is completely saturated with hot moisture and renderedsoft and pliant. While-in this condition I run it through a shreddingmachine so as to reduce it to an uniformly divided fibrous mass. Thefirst 'step is very important [because it obviates splitting and loss ofmaterials during the mechanical d15- integration. The shredded stock isthen subjected to the leaching action of steam and water in order toremove the coloring mat-I The leachter, silica, and other solubles. ingis continued until the liquor shows a density offrom twelve to twentydegrees Baum, more or less, according to the nature of the materialundergoing treatment. The

liquor isthen drawn 'ofi for recovery, and the fibrous stock is washedand then passed Specification of Letters'Patent.

ject of my invention is to recover Patented Aug. 31$, 1919.

. Applicationflled October as, 1916.. Serial m.'12s,2ss.

through a refining engine. The resultant 5 pulp is useful" in themanufacture of cardboardwhen combined with the usual filling and sizingmaterials. By continuing the process from the refin-. mg engine toa'closed digestor wherein I can have a steam pressure of from seventyto' one'hundred pounds or more, and by the addition of an alkali orsul-fid solution, I am enabled to produce an admirable paper making pulpwhich may readily be reduced in the ordinary beater; By my method oftreatment less than half the quantity of alkali or other reducing agentheretofore employed is required so that over'cookin'g and otherdestructive influences are completely obvlated, and the paper of theprocess is characterized by its inherent strength, toughness anddurability. Evidently'bleachmg, s z1ng,.color1ng, etc., may be resortedto if necessary or desirable. 1 i The extractiveor leaching liquor ispreferably treated with a solution of carbonate of lime to remove anyacidity and then a cluding. the residue ofv the treatment, whichpreliminary steaming until it is fully saturated with hot moisturewhereby it is rendered soft and l iant, second, shredding itwhile soconditioned, third, subjecting the shredded stock. to the leachingaction of steam andiwater in order to remove the coloring matter, silicaand other solubles. and continuing this treatment until the liquor has adensity of from twelve to twenty degrees Baum, fourth, drawing oii theleaching liquor and treating it with carbonate of 00 lime preliminary.to the recovery of the products of the leachingtreatment, fifth,washing and refining the fiber, substantially as described.

I In testimony whereof aflix my signature in the presence of twoWitnesses.

MARK W. MARSDEN.

Witnesses:

ALLAN I. Hoenms, E. W... STRAIN.

the nature and object of -85 the inventlon, I claim

